Beyond dimension six in SM Effective Field Theory: a case study in Higgs pair production at NLO QCD

TL;DR

This paper calculates advanced two-loop QCD corrections for Higgs pair production in gluon fusion within SMEFT, comparing different EFT truncation methods and illustrating their phenomenological impacts.

Contribution

It provides the first NLO QCD corrections including squared dimension-6 operators and double insertions in Higgs pair production within SMEFT.

Findings

NLO QCD corrections significantly affect Higgs pair production predictions.

Different EFT truncation schemes lead to notable variations in results.

Comparison with HEFT highlights the importance of EFT expansion choices.

Abstract

We present the NLO (two-loop) QCD corrections to Higgs boson pair production in gluon fusion within Standard Model Effective Theory (SMEFT), including also squared dimension-6 operators and double insertions of operators. The different options to truncate the EFT expansion are contrasted to a non-linear EFT approach (HEFT) and their effects are illustrated by several phenomenological examples.